CC-1000_2018

CC-1000 Companion Guidance (1-2018) CC-1000 Companion Guidance CG Page of 12 Informational 10 CC-1000 Discussion SECTION 8: SOIL GAS EXHAUST VENT PIPE 8.1 General 8.2 Slope 8.3 Prevent air and water leakage 8.8 Pipe routing and thermal insulation 8.5 Pipe support Adequate pipe sizing and the capacity to drain water are critical. Locations of pipe and watertight connections prevent air leaks. For passive systems, route pipe so that it stays warm in cold weather. 8.6 Exhaust vent pipe equivalent length and pressure loss Too much airflow resistance caused by unnecessary elbows and lengthy pipe can compromise effectiveness or energy efficiency for fan choices. Larger pipe sizes are sometimes needed in larger buildings to alleviate this problem. “Equivalent length” and pressure loss Every foot of pipe adds some resistance to airflow due to friction that occurs where the moving air meets the pipe walls. If piping is ridiculously long, even the most powerful fans will be challenged to move enough air. Where elbow and bends are encountered, additional friction occurs. For calculating any air duct designs, an “equivalent length” is calculated for resistance imposed by specific styles of bends or transitions introduced into the duct piping configuration. This allows designs that ensure adequate airflow based on adding together the total pipe length and equivalent lengths. COMMON “EQUIVALENT LENGTH” EXAMPLES Nominal Inside Pipe Diameter 90˚ Sweep 90˚ Sharp 45˚ Sweep 45˚ Sharp 3 inch [7.6 cm] 3 ft (0.9 m) 11 ft (3.4 m) 2 ft (0.6 m) 5 ft (1.5 m) 4 inch [10.2 cm] 6 ft (1.8 m) 15 ft (4.5 m) 3 ft (0.9 m) 6 ft (1.8 m) 6 inch (15.2 cm) 15 ft (4.5 m) 20 ft (6 m) 6 ft (1.8 m) 8.7 Piping materials. 8.8 Joints Durable piping configurations are needed. 8.9 Provision for ASD fan(s) The location of where a fan may be added must be designated prior to installing exhaust piping. Physical access needed for installing a fan also must be provided along with meeting other requirements when exhausting soil gas and electrical service to the fan location. 8.9.5 Provision for ASD fan monitor(s) 8.10 Labels required for exhaust piping The design and location where a fan monitor to be designated prior to installing exhaust piping. Most commonly, pressure gauges are used to view and confirm that the fan is still operating. For larger buildings or complexes, remote monitoring is common.